James h



(No Mbdel.)

J. H. ROBERTSON.

TELEPHONE.

Patented Oct. 27, 1885.

UNITED STATES PATENT OFFICE,

JAMES H. ROBERTSON, OF BROOKLYN, NEW YORK.

TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 329,085, dated October 27, 1885.

Application filed February 14, 1883. Renewed March 20, 1885. Serial No. 159,584. (No model.)

To all whom it may concern:

Be it known that I, JAMES H. ROBERTSON, of the city of Brooklyn, in the county of Kings and State of New York, have invented an Improvement in Telephones, of which the following is a specification, reference being had to the accompanying drawings, forming part of the same, in which Figure l is a side view, partly in section, of a telephone-receiver containing my invention, and Fig. 2 is a rear view of the same.

The invention consists in the combination of the operative parts of a telephone-receiver herein described with the case, specified in the manner set forth.

The operating parts of the receiver consist of the tympan A, carrying the electrode a, the electro-magnet composed of the helix B, the hollow iron core 0, and the armature D, carrying the electrode-point b. In the front part of the said core is placed the spiral spring E, and into the opposite end is inserted a screw-plug, F, which works in a female screw-thread in the core, the plug extending only part way through the core, as shown in Fig. 1. On the outer end of the said spring is fixed the armature D, the opposite end of said spring resting against or being attached to the end of the plug F, as shown. These parts are mounted in a case made of wood, hard rubber, or other analogous material. It is preferably circular in form, consisting of the body G and the cap or cover G.

' H is a handle which is inserted through an opening in one side of the side wall of the case in contact with the inner surface of its rear wall, d. The core is provided with a shoulder, c, and the rear end, which is provided with an exterior screw-thread,is passed through a hole in the upper end of the handle H,and also into or through a screw-threaded hole in the wall d of the case, the shoulder c resting downupon the said handle, whereby the said core, handle, and case are firmly secured together. Preferably the hole through the handle is also screW-threaded,and a screwthread is cut on the core from its rear end to the shoulder c.

The tympan is clamped atits perimeter between the cap G and the rim of the body G, the cap being screwed firmly to the body.-

In the center of the cap is an opening, h, for the emission of sound from the tympan, and its exterior surface is preferably made dishing, as shown in Fig. 1, to enable the listener to place his ear close to the tympan.

e e are bindingposts screwed into the wall (I for connection to the secondary circuit-wires of an induction-coil, (not shown,) the circuitpassing from post 6 through the wire fand helix B, through the handle H, when that is iron, (or directly to either the front or rear end of the core, as may be most' convenient,) to the, core 0, thence through the plug F, spring E, electrodes 1) andc, the tympan A, and wire f, out through the post 6. The described handle may, if preferred, be apermanent magnet.

The described devices, constructed and arranged as shown, constituteja-n economically made and efficient telephonereeeiver.

I do not claim here, broadly, the combination of the operative parts of theinstrum-entnamely, the helix B, core 0, spring E, armature D, tympan A, and electrodes at bthis constituting the subject-matter of a separate application heretofore or contemporaneously filed in the Patent Office.

What I do here claim as my invention, and desire to secure by these Letters Patent, is-

The described operative parts of a telephone-receiver and the case, composed of the body G and top G,- the handle H being inserted tightly in a hole in the wall of the case, and the core 0, which carries the helix B, passing through a hole in the end of the said handle into the base of the said case, all constructed and combined to operate as and for the purpose described.

JAMES H. ROBERTSON.

In presence of P. B. VERMILYA, A. G. N. VERMILYA. 

